Question

我有一个组件，该组件在创建时会从url中提取参数并启动查询。

ngOnInit() {
   ....
 this.id = this.route.snapshot.paramMap.get("my-id");
    console.log("will query db for question with id " + this.id);
    this.myService.getId(this.id)
  }

我想对组件进行单元测试，但是在url创建此组件之前我不知道如何设置TestBed。

网址应为格式

{
    path:'id-details;my-id=:id',//  for eg id-details;my-id=1 
    component:MyComponent
  },

我以为我可以在beforeEach中设置路线，但这不起作用

beforeEach((done) => {
    fixture = TestBed.createComponent(MyComponent);
    component = fixture.componentInstance;
    let router = TestBed.get(Router);
    let location = TestBed.get(Location);
    router.navigateByUrl("/id-details;my-id=1");
  });

  fit('should create', () => {
    expect(component).toBeTruthy();
  });

在以上规范中，组件已创建，但我没有ID。我尝试通过以下两种方法提取参数，但是我总是得到null

 this.id = this.route.snapshot.paramMap.get("my-id"); //get null

和

 this.id = this.route.snapshot.paramMap.get("id-details"); //get null

我还在控制台中看到以下错误

context.js:1972 Navigation triggered outside Angular zone, did you forget to call 'ngZone.run()'?
Unhandled Promise rejection: Cannot match any routes. URL Segment: 'question-details;question-id=1' ; Zone: ProxyZone ; Task: Promise.then ; Value: Error: Cannot match any routes. URL Segment: 'question-details;question-id=1'

Answer 1

尝试一下：

 spyOn(component.route.snapshot.paramMap,"get").and.returnValue("some_id")

或者：

let fake_value = "value";
spyOn(component.route.snapshot.paramMap,"get").and.callFake(()=>{
    return fake_value;
});

fake_value = "another";
component.someMethod();
expect(...).toBe("another");

fake_value = "then_";
component.someMethod();
expect(...).toBe("then_");

如何在单元测试中创建组件之前设置路线

1 个答案: